Improved guard attachment for door-latches



UNITED STATES PATENT OFFICE.

VILLIAM MILLER, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO HIMSELF AND J. B.BRIDGMAN, OF SAME PLACE.

IMPROVED GUARD ATTACHMENT FOR DOOR-LATCHES.

Specification forming part of Letters Patent No. 33,682, dated November5, 1861.

To all whom t may con/cern:

Be it known that I, WILLIAM MILLER, of Boston, in the county of Suffolkand State of Massachusetts, have invented a new and Improved GuardAttachment for Door-Locks; and I do hereby declare that the following isa full, clear, and exact description of the same, reference being had tothe annexed drawings, making a part of this specification, in Which-Figure I is a front view of my invention applied to adoor. Fig. 2 is ahorizontal section of the door, taken in the line Qc x, Fig. l, andshowing a plan or top view of the invention. Fig. 3 is a horizontalsection of the invention, taken in the line y y, Fig. l.

Similarletters of reference indicate corresponding parts in the severalfigures.

The object of this invention is to obtain a simple and eicient devicefor securing the key of a lock at the inner side of a door, so as toprevent the key being turned at the outer side of the door by theapplication of pinchers orpliers-a meansfrequently used by burglars inorder to enter dwellings.

The invention consists in applying a small adjustable slide-bolt to theinner side of the door, and in such a relative position with the keythat the bolt may, when necessary, be shoved through the bow ot' thekey, and thereby prevent the latter being turned at the outer side ofthe door.

To enablethose skilled in the art to fully u nderstandand construct myinvention, I Will proceed to describe it.

A represents a cylindrical socket or tube, which has an arm B attachedto it at right angles, and this arm is secured by a pivot a to ahorizontal lip b, which projects from Va plate c, that is secured to thedoor C in the vicinity of the key-hole of the lock, so that by turningthe arm B in one position the socket A will be inline with the bowel ofthe keyin the lock, and when'turned in theopposite direction be entirelyout of the way of the key. This will be .fully understood by referringto Fig. 2, in which the socket is shown in black turned in line with thebow of the key, and shown turned out of the Way of the bow of the key inred.

In the socket A there is placed a bolt D,

Vpicks or keys.

which is allowed to slide freely in the socket. This bolt D has a pin eattached to it, and this pin fits in a slot f in the side ofthe socket,said slot having a vertical and a horizontal portion, as shown clearlyin Fig. 1, the hori zontal portion of the slot f having notches g madein it, one or more.

The deviceis used as follows: When the key is to be secured in the lock,the operator, after locking` the door, turns the socket A in line withthe bow cl of the key, and then shoves the bolt D upward until the pin ereaches the top ot slot f, the bolt being then turned so that the pin ewill pass into the horizontal part of the slotI and the bolt sustainedthereby, the pin e litting in any of the notches g. The bolt D whenshovedupward passes through the bow cl of the key, as shown in Fig. l,and electually prevents the key being turned in the lock at the outerside ot the door, and said bolt also prevents the key being shoved outfrom the lock to admit of the insertion ot' WVhen it is desired torelease the key, the bolt D is turned so as to bring the pin e in linewith the vertical portion of the slot f and the bolt is allowed to dropin the socket A, Whichis then turned out of line with the key, as shownin red in Fig. 2.

This simple device may be constructed at a small cost and readilyapplied to a door. It is believed that it will prove a valuableacquisition for dwelling-houses and hotels, as the inmates ot' a roomwill by its use be secure against a very common mode practiced byburglars and petty thieves to unlock doors, especially bed-room doors atnight, when the inmates are asleep.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

The socket A, provided with the bolt D, and connected by an arm B andjoint a, tothe plate o, which is attached to the door O at such a pointthat the socket and bolt may have a proper relative position with thebow d of the key, to operate as and for the purpose set forth.

' WM. MILLER.

Witnesses:

JOHN O. PARK, CHARLES E. PIERCE.

